1. Field of the Invention
The present invention relates to a group call server, which provides a plurality of terminals with a function of a group call between the terminals .through a communications network, a group call system configured by comprising the group call server, a terminal, and a group call control method for the group call server, group call system and terminal.
2. Description of the Related Art
Group calls, in which a plurality of users converse using communications terminals through a communications network, have been realized, for example, in telephone conferencing systems, television conferencing systems and the like. Moreover, in the past there have been proposals for systems that use a server as a method to realize group calls in a mobile communications network (for example, refer to Japan Patent Application Laid-open No. 2001-195762). Disclosed in Japan Patent Application Laid-open No. 2001-195762 is a method that not only realizes a group call, but allows a terminal that has been disconnected from the group call for such reasons as being out of the coverage area to reconnect to (rejoin) the group call. Specifically, that method sends a reconnection request (request to rejoin) from the server to the terminal disconnected from the group call, and the terminal receives the reconnection request.